Hudson R L, Gerakines P A, Loeffler M J
Astrochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
Phys Chem Chem Phys. 2015 May 21;17(19):12545-52. doi: 10.1039/c5cp00975h.
New measurements are reported on the weak ν1 and ν2 fundamentals of frozen CH4, a solid of considerable astrochemical interest. Infrared spectra in the ν1 and ν2 regions are presented for three CH4-ice phases at 10-30 K with new absorption coefficients and band strengths to quantify the results. In contrast to the situation with the two crystalline phases of CH4, both ν1 and ν2 were seen clearly in methane's amorphous phase. To support our CH4 work, we also present new results for NH4SH, a component of Jupiter's atmosphere, showing that the ν2 vibration of NH4(+) undergoes a dramatic loss of intensity during an amorphous-to-crystalline phase transition, but is regenerated in equally-dramatic fashion by radiation-induced amorphization of the sample. Results are compared to work recently published in this journal and elsewhere.
报道了关于冻结CH₄的弱ν₁和ν₂基频的新测量结果，CH₄是一种具有相当大天体化学研究价值的固体。给出了在10 - 30 K下三种CH₄冰相在ν₁和ν₂区域的红外光谱，并给出了新的吸收系数和带强度以量化结果。与CH₄的两种晶相情况不同，在甲烷的非晶相中ν₁和ν₂都能清晰地看到。为了支持我们对CH₄的研究工作，我们还给出了木星大气成分NH₄SH的新结果，表明NH₄⁺的ν₂振动在非晶态到晶态的相变过程中强度急剧损失，但通过样品的辐射诱导非晶化以同样显著的方式再生。将结果与最近在本期刊和其他地方发表的研究进行了比较。
